Archive for the ‘Vitamin D’ Category

In June 2010, a vegan who had been diagnosed with vitamin D deficiency wrote me saying that his weekly 50,000 IU of Vitamin D2, prescribed by his doctor for 12 weeks, succeeded in raising his vitamin D levels from 13 ng/ml on Jan 27 to 72 ng/ml on May 4. For long-term maintenance, his doctor recommended 1200 IU per day.

Last November, rumors surfaced that there was a vegan vitamin D3. I’m still occasionally getting questions about it, so I decided to write up what I know.

It appears that these claims have originated with two different brands: MegaFoods and LifeGive.

MegaFoods

I could not find anywhere in which MegaFoods is currently claiming that their vitamin D3 is vegan, but it appears that at one time, someone was claiming that it was. Click here for a write-up about how it is not vegan:

Excerpt:

They say that their vitamin d3 is from S. cerevisiae, and technically it is- however, they actually take regular old vitamin d made from sheep lanolin that anyone can buy in stores, and they ‘feed’ this vitamin d3 to the yeast in order to ‘Biotransform’ the vitamin d3 into what they claim is an effective and bioavailable form of vitamin d3 that is easily ‘utilized’ by the human body.

If you go to their website, Mega Foods doesn’t claim that their vitamin D3 is vegan. A page at Amazon.com claims that MegaFoods’ vitamin D3 does not come from fish and that it is suitable for vegetarians, which I suppose is technically true if they mean lacto-ovo vegetarians who are willing to use sheep’s lanolin.

On November 18, 2009, I wrote UpayaNaturals to inquire about their product and never got a response. However, a JackNorrisRD.com reader, who also wrote them last November, got a response from the company saying, “All the information comes directly from our supplier’s web page.”

I could not find any more information about LifeGive – the company or their Sun D product.

At this time, no one else knows of any way to create vegan D3 and I would say that this casts doubt on whether LifeGive’s Sun D is truly vegan.

In large, single doses, vitamin D3 may be more effective than D2; but in smaller, sustained doses, D2 appears to be as effective. It might take some time to build up your stores of vitamin D by taking D2. Here are my recommendations.

Nature’s Plus Source of Life Garden Vitamin D3

See below in the comments for a discussion of Nature’s Plus D3. A quick summary is that I was not able to verify whether the lab that tested their D3 distinguished between D2 and D3.

Dr. Jacqueline Chan sums up the studies on vitamin D2 vs. D3, “Treatment for most of the studies finding D2 to be less effective than D3 were extremely large boluses given only once, whereas in studies finding them equally effective, the treatment was daily amounts between 400 and 2,000 IU.” (38)

According to Dr. Jacqueline Chan, in order to make vitamin D, “The sun must shine directly on skin without being blocked by sunscreen, glass and most plastics. Glass and most plastics block UVB, the part of the spectrum that converts pro-vitamin D3 but allow passage of UVA which contributes to skin cancer.” (38)

Also according to Dr. Chan, increasing the surface of the skin exposed to the sun proportionately decreases the amount of time needed in the sun to produce the same amount of vitamin D. The duration of the sun exposure should be no more than about half the amount of time it takes for the skin to turn pink. (38)

I have also been getting the impression, based on hearing from people who have been supplementing and getting tested regularly, that it could take large amounts of vitamin D2 (1,000 – 2,000 IU per day) over the course of months to see a significant increase in 25(OH)D levels.

Here are some studies addressing the question of whether tanning beds are a safe and reliable source of vitamin D.

A 2004 study found that tanners had much higher levels of vitamin D (and lower rates of vitamin D deficiency) than non-tanning bed users. They noted that to produce vitamin D, the tanning bed must emit ultraviolet B rays of 290–315 nm. This study did not indicate that they screened subjects based on the UV ray type of the tanning bed they used. A link to entire study is below (1). This study was confounded by the fact that the tanners stayed out in the sun significantly longer than non-tanners (2).

In their 2010 paper, Woo and Eide state that most tanning “devices” emit ultraviolet A rays, which do not produce much vitamin D (2). They say:

“Given the relative inefficiency of UVA-emitting tanning devices in increasing serum vitamin D levels, especially in those most at risk of vitamin D deficiency, indoor tanning is not recommendable as a way to achieve optimal vitamin D levels in the general public.”

The authors also argue that for tanning to occur, DNA damage must also occur. In fact, the American Academy of Dermatology (AAD) says, “There is no scientifically validated, safe threshold level of UV exposure from the sun or indoor tanning devices that allows for maximal vitamin D synthesis without increasing skin cancer risk (3).” The AAD recommends against using even sunlight to raise vitamin D levels.

In summary, it appears that you can get vitamin D from tanning beds if you make sure the bed uses UV B rays of 290–315 nm, but doing so can raise the risk of skin cancer.

This abstract shows that exposing one serving (84 g) of post-harvest, white button mushrooms to UVB rays for 5 minutes resulted in their having 86.9 µg (3,476 IU) vitamin D2, which is well above the recommended daily intake.

So if you see mushrooms in the store labeled as having 100% of the Daily Value or RDA for vitamin D, it’s probably true.

In 2008, the American Academy of Pediatrics raised its recommendations for infants from 5 µg (200 IU) of vitamin D per day to 10 µg (400 IU). They stated, “It is now recommended that all infants and children, including adolescents, have a minimum daily intake of 400 IU of vitamin D beginning soon after birth.” (4)

4. Wagner CL, Greer FR, and the Section on Breastfeeding and Committee on Nutrition. Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents. Pediatrics 2008;122:1142-1152.

It is the end of the winter and the time of year when people’s vitamin D levels will naturally be the lowest. I am hearing from a disconcerting number of vegans (4 to be exact) who have had their vitamin D levels tested in the last month or so and have been well below normal, and close to zero in some cases. Three of these people have lived in San Diego, Santa Monica, and San Jose, which means living in a sunny climate does not guarantee you are getting enough vitamin D, unfortunately.

A 2010 study on obese African-Americans with type 2 diabetes showed that those with higher blood levels of vitamin D had more calcification of some arteries (but not others) (35). In a related article, Vitamin D levels have different effects on atherosclerosis in blacks and whites, the lead researcher, Barry I. Freedman, MD, stated, “We should use caution when supplementing vitamin D in black patients while we investigate if we are actually worsening calcium deposition in the arteries with treatment.” That said, there has also been concern about black people not getting enough vitamin D (36). It seems prudent, then, for black people to get moderate amounts of sun and if they cannot, to supplement with smaller amounts of vitamin D, such as 250 IU per day. It seems prudent, then, for black people who have type 2 diabetes not to overdo vitamin D supplementation and take closer to the DRI until more research is conducted.

A couple days ago, someone posted to the SFBAVeg email list that they saw some white mushrooms in Safeway advertised as having 100% RDA for vitamin D. I was aware that some mushrooms had small amounts of vitamin D2 in them, but 100% of the RDA (5 mcg / 200 IU) was a surprise.

A follow up post linked to the article Light-zapped mushrooms filled with vitamin D, from 2006, which reported a study being conducted measuring the levels of vitamin D2 in mushrooms exposed to ultraviolet (UV) rays. I then went to PubMed and found a few abstracts (listed below) of completed studies indicating that exposing mushrooms to uv rays does increase their vitamin D content.

I’m not sure what the exact content of vitamin D in such mushrooms tends to be, but if it is about the RDA per serving, then one serving is still far short of the 25 mcg (1,000 IU) that recent research indicates might be needed for optimal health (for people not getting much sunlight). That said, eating UV treated mushrooms could be a big boost.

The Fall 2009 issue of Vegetarian Voice magazine, the newsletter of the North American Vegetarian Society, has an article by Amy Joy Lanou and Michael Castleman, “A Whole Diet Approach to Building Better Bones.”

I will quote from the article to sum up their arguments:

“[W]e have known for at least 20 years that fracture rates are highest in areas where dairy and calcium consumption are also the highest.”

“Research shows that a low-acid diet, one that is high in fruits and vegetables and devoid of (or low in) animal protein (meats, poultry, fish, milk, eggs and cheese) helps keep calcium in bones.”

“[Osteoporosis is] actually a disease of calcium imbalance. Drinking milk and eating dairy foods provides calcium – but these foods are so high in protein that they draw more calcium out of bone then they replace.”

“We do need some calcium. The World Health Organization recommends 400 to 500 mg/day for people in countries at high risk of osteoporosis.”

“The best approach to osteoporosis prevention – the only one that makes scientific sense – is a diet very low in or devoid of animal foods and high in fruits and vegetables, combined with walking or equivalent exercise for 30 to 60 minutes a day, every day.”

If you have been following vegan nutrition advocacy for the past two decades, nothing above should be new to you. And here are the major problems I have with it:

1. Most non-vegans in Western countries get around 800 to 1200 mg of calcium per day. At this level of intake, I agree that there is little evidence that to prevent osteoporosis one needs even more calcium. However, Lanou and Castleman imply that all you need is a vegan diet containing 400 – 500 mg of calcium per day and walking for 30 to 60 minutes for strong bones. And they leave out the most important study published to date on bone health and vegans, a 2007 report from the EPIC-Oxford study which showed that vegans had a 30% higher rate of bone fractures than did meat-eaters and lacto-ovo vegetarians!

In that study, the vegans who got more than 525 mg of calcium had the same rate of bone fractures as the meat-eaters and lacto-ovo vegetarians, showing that vegans need more than 525 mg of calcium. (In the study, 32% of vegans had calcium intakes between 525 and 699 mg per day, and 24% had greater than 699 mg per day.)

This is the only study looking at the bone fracture rates of vegans.

2. Lanou and Castleman base most of their argument on the idea that animal protein leeches calcium from the bones. As I posted a few weeks ago, a meta-analysis looking at bone health and fractures found that “Overall, the weight of the evidence shows that the effect of dietary protein [including animal protein] on the skeleton appears to be favorable to a small extent or, at least, is not detrimental.”

In my opinion, the argument that a primary cause of osteoporosis is animal protein has always been on shaky ground.

3. Lanou and Castleman leave vitamin D out of their final recommendations (they briefly mention you can get it from the sun earlier in the article). Vitamin D can be a significant problem for many vegans and needs to be addressed in discussions of bone health.

4. I do not see why it is necessary to make an argument that people only need 400 to 500 mg of calcium per day, when the evidence is so lacking (and actually points in the other direction). What harm could come from encouraging vegans to get at least the low end of what is a normal amount of calcium (like 700 to 800 mg/day) in Western countries? None. But what harm could come from vegans not getting that much? Only osteoporosis!

In summary, there is no direct evidence that a vegan diet with only 400 to 500 mg of calcium per day prevents osteoporosis. The direct evidence is just the opposite.